Vehicle lighting device and vehicle lamp

Abstract

To provide a vehicle lighting device which can produce a desired luminance distribution even if the number of light emitting elements is increased.SOLUTION: A vehicle lighting device comprises a socket, a baseboard, one first light emitting element 22a on the baseboard, and four second light emitting elements 22b. A square luminance distribution region 120 orthogonal to a center axis of the vehicle lighting device is defined on a light irradiation side of the first light emitting element 22a and the second light emitting elements 22b. A center of the luminance distribution region 120 overlaps the center axis of the vehicle lighting device. The luminance distribution region 120 is equally divided into four square first regions 121 with their corners overlapping the center of the luminance distribution region 120, and the four first regions 121 are equally divided into nine square second regions 122. Planar shapes of the first light emitting element 22a and the second light emitting elements 22b are square, and a first side of the square of the first light emitting element 22a and a second side of the square of the second light emitting elements 22b which is opposite the first side are parallel with each other.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to a vehicle lighting device and a vehicle lamp. [Background technology]

[0002] 2. Description of the Related Art From the viewpoint of energy saving and long life, vehicle lighting devices equipped with light emitting elements such as light emitting diodes are becoming increasingly popular instead of vehicle lighting devices equipped with filaments. In recent years, there has been a demand for vehicle lighting devices with higher luminous flux. In this case, the vehicle lighting device can achieve higher luminous flux by increasing the number of light-emitting elements provided therein.

[0003] However, simply increasing the number of light-emitting elements makes it difficult to achieve a desired luminance distribution. In this case, for example, if the balance between the luminance distribution in the peripheral region of the light exit surface and the luminance distribution in the central region of the light exit surface becomes poor, it may become difficult to form a desired light distribution pattern. Therefore, there has been a demand for the development of a technology that can achieve a desired luminance distribution even when the number of light-emitting elements is increased. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2021 / 206145 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a vehicle lighting device and a vehicle lamp that can achieve a desired luminance distribution even when the number of light-emitting elements is increased. [Means for solving the problem]

[0006] A vehicle lighting device according to an embodiment includes a socket; a substrate provided on one end of the socket; one first light-emitting element provided on the substrate; and four second light-emitting elements provided on the substrate. A square luminance distribution region perpendicular to the central axis of the vehicle lighting device is defined on the light emission side of the first light-emitting element and the second light-emitting element. The center of the luminance distribution region overlaps with the central axis of the vehicle lighting device. The luminance distribution region is equally divided into four square first regions whose corners overlap with the center of the luminance distribution region. The four square Each of the first regions is equally divided into nine square second regions. The length of one side of the second regions is 0.8 mm. When the XY coordinates of the center of the luminance distribution region are (0, 0), the center of the first light-emitting element is located at (0, 0), and the centers of the four second light-emitting elements are located at (0.8, 0.8), (-0.8, 0.8), (0.8, -0.8), and (-0.8, -0.8). The luminance of the luminance distribution region is 90% or more of the overall luminance of light emitted from the vehicle lighting device. Of the 20 second regions arranged along the sides of the luminance distribution region, the luminance of one of the second regions is 2% or less of the overall luminance. Of the 16 second regions arranged inside the 20 second regions, the luminance of one of the second regions is 3% or more and 10% or less of the overall luminance. The planar shape of the first light-emitting element and the planar shape of the second light-emitting element are rectangular, and a first side of the rectangle of the first light-emitting element and a second side of the rectangle of the second light-emitting element opposite to the first side are parallel to each other. [Effects of the Invention]

[0007] According to the embodiments of the present invention, it is possible to provide a vehicle lighting device and a vehicle lamp that can achieve a desired luminance distribution even when the number of light-emitting elements is increased. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic perspective view illustrating a vehicle lighting device according to an embodiment of the present invention; [Figure 2] 2 is a cross-sectional view of the vehicle lighting device taken along line AA in FIG. 1. [Figure 3] FIG. 2 is a schematic plan view illustrating the arrangement of five light-emitting elements. [Figure 4] FIG. 2 is a circuit diagram of the light-emitting module. [Figure 5] FIG. 2 is a schematic partial cross-sectional view illustrating a vehicle lamp. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be illustrated with reference to the drawings. In the drawings, like components are designated by like reference numerals and detailed descriptions thereof will be omitted where appropriate. In addition, arrows X, Y, and Z in each figure represent directions that are perpendicular to one another. For example, arrow X represents the left-right direction or the up-down direction, arrow Y represents the up-down direction or the left-right direction, and arrow Z represents the front-rear direction. For example, arrow Z may be a direction along the central axis 1a of the vehicle lighting device 1.

[0010] (Vehicle lighting device) The vehicle lighting device 1 according to this embodiment can be installed in, for example, an automobile, a railway vehicle, etc. Examples of the vehicle lighting device 1 installed in an automobile include those used as front combination lights (for example, an appropriate combination of daytime running lamps (DRLs), position lamps, turn signal lamps, etc.) and rear combination lights (for example, an appropriate combination of stop lamps, tail lamps, turn signal lamps, backup lamps, fog lamps, etc.). However, the uses of the vehicle lighting device 1 are not limited to these.

[0011] FIG. 1 is a schematic perspective view illustrating a vehicle lighting device 1 according to the present embodiment. FIG. 2 is a cross-sectional view of the vehicle lighting device 1 taken along line AA in FIG. As shown in FIGS. 1 and 2, a vehicle lighting device 1 includes, for example, a socket 10, a light-emitting module 20, a power supply unit 30, and a heat transfer unit 40.

[0012] The socket 10 includes, for example, a mounting portion 11, a bayonet 12, a flange 13, heat dissipation fins 14, and a connector holder 15. The mounting portion 11 is provided, for example, on the surface of the flange 13 opposite to the side on which the heat dissipation fins 14 are provided. The outer shape of the mounting portion 11 can be columnar. The outer shape of the mounting portion 11 is, for example, cylindrical. The mounting portion 11 has, for example, a recess 11a that opens at the end opposite to the flange 13 side.

[0013] The bayonet 12 is provided, for example, on the side surface of the mounting portion 11. The bayonet 12 protrudes, for example, toward the outside of the vehicle lighting device 1. The bayonet 12 faces the flange 13. A plurality of bayonets 12 may be provided. The bayonet 12 is used when mounting the vehicle lighting device 1, for example, to a housing 101 of a vehicle lamp 100 described below. The bayonet 12 can be used for a twist lock.

[0014] The flange 13 has, for example, a plate shape. The flange 13 has, for example, a disk shape. A side surface of the flange 13 is located outward of the side surface of the bayonet 12 from the vehicle lighting device 1.

[0015] The heat dissipation fin 14 is provided, for example, on the side of the flange 13 opposite to the mounting portion 11 side. At least one heat dissipation fin 14 can be provided. For example, the socket 10 illustrated in FIG. 1 is provided with a plurality of heat dissipation fins 14. The plurality of heat dissipation fins 14 can be arranged side by side in a predetermined direction. The heat dissipation fin 14 has, for example, a plate or cylindrical shape.

[0016] The connector holder 15 is provided, for example, on the side of the flange 13 opposite to the mounting portion 11. The connector holder 15 can be provided alongside the heat dissipation fins 14. The connector holder 15 is cylindrical, and a connector 105 having a sealing member 105a therein is inserted into the connector holder 15.

[0017] The socket 10 has the function of holding the light-emitting module 20 and the power supply unit 30, and the function of conducting heat generated in the light-emitting module 20 to the outside. Therefore, the socket 10 is preferably made of a material with high thermal conductivity. For example, the socket 10 can be made of a metal such as an aluminum alloy.

[0018] In recent years, it has become desirable for the socket 10 to be lightweight and capable of efficiently dissipating heat generated in the light-emitting module 20. Therefore, it is more preferable that the socket 10 be formed from, for example, a highly thermally conductive resin. The highly thermally conductive resin includes, for example, a resin and a filler using an inorganic material. The highly thermally conductive resin is, for example, a resin such as PET (Polyethylene terephthalate) or nylon mixed with a filler using carbon, aluminum oxide, or the like.

[0019] If the socket 10 contains a highly thermally conductive resin and has the mounting portion 11, bayonet 12, flange 13, heat dissipation fins 14, and connector holder 15 integrally molded, the heat generated in the light-emitting module 20 can be efficiently dissipated. The weight of the socket 10 can also be reduced. In this case, the mounting portion 11, bayonet 12, flange 13, heat dissipation fins 14, and connector holder 15 can be integrally molded using injection molding or the like. Alternatively, the socket 10, power supply portion 30, and heat transfer portion 40 can be integrally molded using insert molding or the like.

[0020] The power supply unit 30 includes, for example, a plurality of power supply terminals 31 and a holding unit 32 . The plurality of power supply terminals 31 may be rod-shaped. The plurality of power supply terminals 31 may be arranged side by side in a predetermined direction. One end of each of the plurality of power supply terminals 31 protrudes from the bottom surface 11a1 of the recess 11a. One end of each of the plurality of power supply terminals 31 is soldered to the wiring pattern 21a provided on the substrate 21. The other end of each of the plurality of power supply terminals 31 is exposed inside the hole of the connector holder 15. The connector 105 is fitted to the end of each of the plurality of power supply terminals 31 exposed inside the hole of the connector holder 15. The plurality of power supply terminals 31 are formed from a metal such as a copper alloy. The shape, arrangement, material, etc. of the plurality of power supply terminals 31 are not limited to those exemplified and may be changed as appropriate.

[0021] As described above, the socket 10 is preferably made of a material with high thermal conductivity. However, materials with high thermal conductivity may be electrically conductive. For example, metals such as aluminum alloys and highly thermally conductive resins containing a carbon-based filler are electrically conductive. Therefore, the retaining portion 32 is provided to insulate the multiple power supply terminals 31 from the electrically conductive socket 10. The retaining portion 32 also functions to hold the multiple power supply terminals 31. If the socket 10 is made of an insulating, highly thermally conductive resin (e.g., a highly thermally conductive resin containing an aluminum oxide filler), the retaining portion 32 can be omitted. In this case, the socket 10 holds the multiple power supply terminals 31. The retaining portion 32 is made of, for example, an insulating resin. The retaining portion 32 can be press-fitted into a hole 10a provided in the socket 10 or adhered to the inner wall of the hole 10a.

[0022] The heat transfer member 40 is provided, for example, between the substrate 21 and the bottom surface 11a1 of the recess 11a. The heat transfer member 40 can be attached to the bottom surface 11a1 of the recess 11a. The adhesive that bonds the heat transfer member 40 to the bottom surface 11a1 of the recess 11a is preferably an adhesive with high thermal conductivity. For example, the adhesive can be an adhesive mixed with a filler that uses an inorganic material. The inorganic material is preferably a material with high thermal conductivity (for example, ceramics such as aluminum oxide or aluminum nitride).

[0023] The heat transfer unit 40 can also be embedded in the bottom surface 11a1 of the recess 11a by insert molding. The heat transfer unit 40 can also be attached to the bottom surface 11a1 of the recess 11a via a layer containing thermally conductive grease (heat dissipating grease). There are no particular limitations on the type of thermally conductive grease, but for example, the thermally conductive grease can be a mixture of modified silicone and a filler using a material with high thermal conductivity (for example, ceramics such as aluminum oxide or aluminum nitride).

[0024] The heat transfer section 40 is provided to facilitate the transfer of heat generated in the light-emitting module 20 to the socket 10. For this reason, the heat transfer section 40 is preferably made of a material with high thermal conductivity. The heat transfer section 40 has a plate shape and can be made of a metal such as aluminum, an aluminum alloy, copper, or a copper alloy. It should be noted that if the amount of heat generated in the light-emitting module 20 is small, the heat transfer section 40 may be omitted.

[0025] The light-emitting module 20 (substrate 21) is provided, for example, on one end side of the socket 10. The light-emitting module 20 (substrate 21) is, for example, adhered onto the heat transfer section 40. If the heat transfer section 40 is omitted, the light-emitting module 20 (substrate 21) is, for example, adhered to the bottom surface 11a1 of the recess 11a. The adhesive that adheres the light-emitting module 20 (substrate 21) can be, for example, the same as the adhesive that adheres the heat transfer section 40 and the bottom surface 11a1 of the recess 11a. The light emitting module 20 includes, for example, a substrate 21, a light emitting element 22, a frame 23, a sealing portion 24, an optical element 25, and an element 26.

[0026] The substrate 21 has a plate-like shape. The planar shape of the substrate 21 is, for example, a rectangle. The substrate 21 can be formed from, for example, an inorganic material such as ceramics (e.g., aluminum oxide or aluminum nitride), or an organic material such as paper phenol or glass epoxy. The substrate 21 may also be a metal core substrate in which the surface of a metal plate is coated with an insulating material. When the light emitting element 22 generates a large amount of heat, it is preferable to form the substrate 21 using a material with high thermal conductivity from the perspective of heat dissipation. Examples of materials with high thermal conductivity include ceramics such as aluminum oxide or aluminum nitride, highly thermally conductive resins, and metal core substrates. The substrate 21 may have a single-layer structure or a multi-layer structure.

[0027] The substrate 21 also has a wiring pattern 21a. The wiring pattern 21a is provided on the surface of the substrate 21. The wiring pattern 21a contains, for example, a material containing silver as a main component or a material containing copper as a main component.

[0028] The light emitting element 22 is provided on the substrate 21 (the side opposite to the heat transfer section 40). The light emitting element 22 is electrically connected to the wiring pattern 21a. A plurality of light emitting elements 22 are provided. For example, five light emitting elements 22 can be provided. The light emitting element 22 may be, for example, a light emitting diode, an organic light emitting diode, a laser diode, or the like.

[0029] The light emitting element 22 may be a chip-shaped light emitting element. The chip-shaped light emitting element 22 can reduce the size of the light emitting module 20 and, in turn, the size of the vehicle lighting device 1 compared to a surface-mounted light emitting element or a light emitting element having a lead wire, such as a bullet-shaped light emitting element.

[0030] The light emitting element 22 can be mounted on the wiring pattern 21a by COB (Chip On Board). The light emitting element 22 may be, for example, any of an upper electrode type light emitting element, a top and bottom electrode type light emitting element, and a flip chip type light emitting element. The planar shape of the light emitting element 22 (the shape of the light emitting surface) can be a rectangle.

[0031] FIG. 3 is a schematic plan view illustrating the arrangement of five light-emitting elements 22. As shown in FIG. 3 is a schematic diagram of the five light-emitting elements 22 viewed from a direction (Z direction) along the central axis 1a of the vehicle lighting device 1. To avoid complexity, elements other than the five light-emitting elements 22 are omitted from the drawing.

[0032] 3, a luminance distribution region 120 is defined. The shape of the luminance distribution region 120 is a square. One side of the luminance distribution region 120 is parallel to the X direction. The other side of the luminance distribution region 120 is parallel to the Y direction. That is, a square luminance distribution region 120 perpendicular to the central axis 1a of the vehicle lighting device 1 is defined on the light emitting side of the five light emitting elements 22. The center of the luminance distribution region 120 overlaps with the central axis 1 a of the vehicle lighting device 1 .

[0033] The luminance distribution region 120 is equally divided into four square regions 121 (corresponding to an example of a first region) whose corners overlap the center of the luminance distribution region 120. Each of the four regions 121 is equally divided into nine square regions 122 (corresponding to an example of a second region). The length of one side of the luminance distribution region 120 is, for example, 4.8 mm, the length of one side of the region 121 is, for example, 2.4 mm, and the length of one side of the region 122 is, for example, 0.8 mm.

[0034] 3, one light-emitting element 22a (corresponding to an example of a first light-emitting element) can be provided at the center of the luminance distribution region 120 (the position of the central axis 1a of the vehicle lighting device 1). For example, the center of the light-emitting element 22a can overlap with the center of the luminance distribution region 120.

[0035] Four light-emitting elements 22b (corresponding to an example of a second light-emitting element) can be provided surrounding the light-emitting element 22a. For example, the center of the light-emitting element 22b can be overlapped with a corner of the region 122 having a corner overlapping with the center of the luminance distribution region 120, the corner being diagonally opposite the corner overlapping with the center of the luminance distribution region 120.

[0036] For example, if the XY coordinates of the center of the luminance distribution region 120 are (0, 0), the center of the light-emitting element 22a can be located at (0, 0). The centers of the four light-emitting elements 22b can be located at (0.8, 0.8), (-0.8, 0.8), (0.8, -0.8), and (-0.8, -0.8).

[0037] In this way, the light emitting element 22a can be provided at the center of the luminance distribution region 120. Furthermore, the light emitting element 22b can be provided in each of the four regions 121 surrounding the center of the luminance distribution region 120. This makes it easy to irradiate light isotropically in the X and Y directions.

[0038] Furthermore, the luminance of the luminance distribution region 120 can be set to 90% or more of the luminance (total luminance) of the light emitted from the vehicle lighting device 1 (light-emitting module 20). Furthermore, among the 20 regions 122 arranged along the sides of the luminance distribution region 120, the luminance of one region 122 can be set to 2% or less of the overall luminance. Furthermore, among the 16 regions 122 provided inside the 20 regions 122 aligned along the sides of the luminance distribution region 120, the luminance of one region 122 can be set to 3% or more and 10% or less of the overall luminance.

[0039] The planar shape of the light emitting element 22a and the light emitting element 22b can be a square or a rectangle. In this case, the planar shapes of the light emitting element 22a and the light emitting element 22b may be the same or different.

[0040] The planar dimensions of the light-emitting element 22a and the light-emitting element 22b may be the same or different. For example, the planar dimensions of the light-emitting element 22b may be larger than, the same as, or smaller than the planar dimensions of the light-emitting element 22a. That is, at least one of the planar shape and planar dimensions of the light emitting element 22b can be the same as those of the light emitting element 22a, or the planar shape and planar dimensions of the light emitting element 22b can be different from those of the light emitting element 22a.

[0041] For example, the length of one side of the light emitting element 22a having a square planar shape can be set to about 0.48 mm, and the length of one side of the light emitting element 22b having a square planar shape can be set to about 0.73 mm.

[0042] Furthermore, as shown in FIG. 3, the sides of the light-emitting element 22a and the sides of the light-emitting element 22b can be parallel to each other. As mentioned above, the light-emitting element 22a and the light-emitting element 22b may be top-and-bottom electrode light-emitting elements. When top-and-bottom electrode light-emitting elements are connected in series, the polarity of the lower electrode of one light-emitting element differs from the polarity of the lower electrode of an adjacent light-emitting element. Therefore, it is preferable to increase the distance between the wiring pattern 21a on which one light-emitting element is mounted and the wiring pattern 21a on which the adjacent light-emitting element is mounted to increase the creepage distance. By making the sides of the light-emitting element 22a and the sides of the light-emitting element 22b parallel to each other, the distance between the wiring patterns 21a can be increased even if the distance between the centers of the light-emitting elements 22a and 22b is the same. This can prevent short circuits and other problems from occurring.

[0043] The frame portion 23 is provided on the substrate 21. The frame portion 23 has a frame shape and is adhered to the substrate 21. A plurality of light-emitting elements 22 are provided in the area surrounded by the frame portion 23. The frame portion 23 is formed from, for example, a resin. The resin may be, for example, a thermoplastic resin such as PBT (polybutylene terephthalate), PC (polycarbonate), PET, nylon, PP (polypropylene), PE (polyethylene), or PS (polystyrene).

[0044] The frame 23 can have a function of defining the formation area of ​​the sealing portion 24 and a function of a reflector. Therefore, the frame 23 can contain titanium oxide particles or a white resin in order to improve reflectance.

[0045] Moreover, the frame portion 23 can be omitted. However, if the frame portion 23 is provided, it is possible to improve the utilization efficiency of the light emitted from the light-emitting element 22. Furthermore, since the area where the sealing portion 24 is formed can be reduced, it is possible to reduce the size of the light-emitting module 20, and therefore the size of the vehicle lighting device 1.

[0046] The sealing portion 24 is provided inside the frame portion 23. The sealing portion 24 is provided so as to cover the area surrounded by the frame portion 23. The sealing portion 24 is provided so as to cover the light-emitting element 22. The sealing portion 24 contains a light-transmitting resin. The sealing portion 24 is formed, for example, by filling the inside of the frame portion 23 with resin. The filling of the resin is performed, for example, using a dispenser or the like. The resin to be filled is, for example, a silicone resin or the like. When the frame portion 23 is omitted, for example, a dome-shaped sealing portion 24 is provided on the substrate 21.

[0047] Furthermore, the sealing portion 24 may contain a phosphor. The phosphor may be, for example, a YAG-based phosphor (yttrium-aluminum-garnet-based phosphor). However, the type of phosphor may be changed as appropriate to obtain a predetermined emission color depending on the application of the vehicle lighting device 1.

[0048] The optical element 25 can be provided on the sealing portion 24. The optical element 25 can be, for example, a convex lens, a concave lens, a light guide, or the like. The optical element 25 illustrated in FIG. 2 is a convex lens. The optical element 25 is not necessarily required and can be omitted. However, if the optical element 25 is provided, it becomes easier to obtain a predetermined light distribution characteristic.

[0049] The element 26 can be a passive element or an active element used to configure a light emitting circuit having the light emitting element 22. The element 26 is provided, for example, on the periphery of the frame portion 23 and is electrically connected to the wiring pattern 21a.

[0050] The element 26 may be, for example, a resistor 26a, a diode 26b, and a control element 26c. However, the type of element 26 is not limited to the example given, and can be changed as appropriate depending on the configuration of the light-emitting circuit having the light-emitting element 22. For example, in addition to the above, element 26 may also be a capacitor, a positive temperature coefficient thermistor, a negative temperature coefficient thermistor, a Zener diode, an inductor, a surge absorber, a varistor, a transistor such as an FET or a bipolar transistor, an integrated circuit, or an arithmetic element.

[0051] The resistor 26a is provided on the substrate 21. The resistor 26a is electrically connected to the wiring pattern 21a. The resistor 26a may be, for example, a surface-mount resistor, a resistor with leads (metal oxide film resistor), or a film resistor formed using a screen printing method or the like. The resistor 26a illustrated in FIG. 1 is a film resistor.

[0052] The film resistor is made of, for example, ruthenium oxide (RuO2). The film resistor is formed by, for example, screen printing and firing. If the resistor 26a is a film resistor, the contact area between the resistor 26a and the substrate 21 can be increased, thereby improving heat dissipation. Furthermore, multiple resistors 26a can be formed at once, thereby improving productivity. Furthermore, variations in the resistance values ​​of the multiple resistors 26a can be suppressed.

[0053] Here, since there is variation in the forward voltage characteristics of the light-emitting element 22, if the voltage applied between the anode terminal and the ground terminal is constant, variation occurs in the brightness (luminous flux, luminance, luminous intensity, illuminance) of the light emitted from the light-emitting element 22. Therefore, to keep the brightness of the light emitted from the light-emitting element 22 within a predetermined range, the value of the current flowing through the light-emitting element 22 is controlled to be within a predetermined range by using a resistor 26a connected in series to the light-emitting element 22. In this case, the resistance value of the resistor 26a is changed to keep the value of the current flowing through the light-emitting element 22 within the predetermined range.

[0054] If the resistor 26a is a surface-mount resistor or a resistor with leads, the resistor 26a should have an appropriate resistance value depending on the forward voltage characteristics of the light-emitting element 22. If the resistor 26a is a film resistor, the resistance value can be increased by removing a portion of the resistor 26a. For example, a portion of the film resistor can be easily removed by irradiating the film resistor with laser light. The number, size, and arrangement of the resistors 26a are not limited to those illustrated, and can be changed as appropriate depending on the number and specifications of the light-emitting elements 22.

[0055] The diode 26b is provided on the substrate 21. The diode 26b is electrically connected to the wiring pattern 21a. The diode 26b is electrically connected between the power supply terminal 31 and the light-emitting element 22 and the control element 26c. The diode 26b is provided, for example, to prevent a reverse voltage from being applied to the light-emitting element 22 and the control element 26c, and to prevent pulse noise from being applied from the reverse direction to the light-emitting element 22 and the control element 26c. The diode 26b is, for example, a surface-mounted diode or a diode with leads. The diode 26b illustrated in FIG. 1 is a surface-mounted diode.

[0056] Here, the voltage (input voltage) applied to the vehicle lighting device 1 may fluctuate. For example, the standard operating voltage (rated voltage) of a vehicle lighting device 1 for a typical automobile is about 13.5V. However, the input voltage may fluctuate due to factors such as a drop in battery voltage, alternator operation, and circuit influences. For this reason, an operating voltage range (voltage fluctuation range) is specified for vehicle lighting devices 1 for automobiles. The operating voltage range is, for example, 9V or higher and 16V or lower.

[0057] Furthermore, for example, if the forward voltage Vf of the light-emitting element 22 is 1.8 V, when five light-emitting elements 22 are connected in series and the input voltage approaches 9 V, almost no current flows through the five light-emitting elements 22, and the total luminous flux of the vehicle lighting device 1 falls below the specified value. Furthermore, resistors 26 a and diodes 26 b are also connected in series to the five light-emitting elements 22. Therefore, it becomes even more difficult to ensure the total luminous flux of the vehicle lighting device 1 near the lower limit of the operating voltage range.

[0058] Therefore, the light emitting module 20 is provided with a control element 26c. FIG. 4 is a circuit diagram of the light emitting module 20. As shown in FIG. As shown in FIG. 4, the control element 26c is electrically connected between the resistor 26a and the five light-emitting elements 22.

[0059] The control element 26c is provided on the substrate 21. The control element 26c is electrically connected to the five light-emitting elements 22 (22a, 22b) via the wiring pattern 21a.

[0060] The control element 26c detects the input voltage and switches the number of light-emitting elements 22 through which current flows, depending on the detected input voltage. In this case, the control element 26c can switch the number of light-emitting elements 22b through which current flows, depending on the detected input voltage. For example, when the input voltage is higher than a predetermined voltage, the control element 26c flows current through the five light-emitting elements 22 (22a, 22b) connected in series. When the input voltage is lower than the predetermined voltage, the control element 26c flows current through the three light-emitting elements 22 (22a, 22b) connected in series, but does not flow current through the other two light-emitting elements 22 (22b) connected in series.

[0061] If the control element 26c is provided, it is possible to prevent the current flowing through the three light-emitting elements 22 from decreasing when the input voltage drops, and therefore it is possible to ensure the total luminous flux required when the input voltage drops.

[0062] Here, to achieve a total luminous flux of 180 lumens (lm) ±15%, if the five light-emitting elements 22 are red light-emitting diodes with an operating voltage of 1.9V to 2.5V, the applied power is 3W to 4W, and the ambient temperature is 25°C, the junction temperature of the light-emitting elements 22 will be approximately 55°C to 90°C. However, the difference between the junction temperature immediately after lighting and the junction temperature 30 minutes after lighting becomes large, resulting in a large luminous flux change rate. If the luminous flux change rate becomes large, the driver of the vehicle may feel uncomfortable, for example.

[0063] Therefore, the control element 26c may have a soft start circuit. For example, the control element 26c controls the current flowing through the five light-emitting elements 22 (22a, 22b) immediately after lighting to be 60% to 70% of the current flowing through the five light-emitting elements 22 (22a, 22b) 30 minutes after lighting.

[0064] Furthermore, the temperature of the region of the substrate 21 where the five light-emitting elements 22 (22a, 22b) are provided may reach or exceed 100° C. In such cases, it is necessary to prevent the junction temperature from exceeding the maximum junction temperature (for example, 150° C.). Therefore, the control element 26c can have a derating circuit. For example, the control element 26c detects the ambient temperature, and when the ambient temperature is above 80°C and below 110°C, the control element 26c limits the power applied to the five light-emitting elements 22 (22a, 22b) to 60% to 70% of the rated power. In this way, the junction temperatures of the five light-emitting elements 22 (22a, 22b) can be prevented from exceeding the maximum junction temperature.

[0065] (vehicle lighting fixtures) In one embodiment of the present invention, a vehicle lamp 100 can be provided that includes the vehicle lighting device 1. The above-mentioned description of the vehicle lighting device 1 and modified versions of the vehicle lighting device 1 (for example, versions in which a person skilled in the art appropriately adds, deletes, or modifies components, and which still have the features of the present invention) can all be applied to the vehicle lamp 100.

[0066] In the following, as an example, a case where the vehicular lamp 100 is a rear combination light installed in an automobile will be described. However, the vehicular lamp 100 is not limited to a rear combination light installed in an automobile. The vehicular lamp 100 may be any vehicular lamp that is installed in an automobile, a railroad car, or the like.

[0067] FIG. 5 is a schematic partial cross-sectional view illustrating the vehicle lamp 100. As shown in FIG. As shown in FIG. 5, the vehicle lamp 100 includes, for example, the vehicle lighting device 1, a housing 101, a cover 102, an optical element 103, a seal member 104, and a connector 105.

[0068] The vehicle lighting device 1 is attached to the housing 101. The housing 101 holds the mounting portion 11. The housing 101 is box-shaped with one end open. The housing 101 is formed, for example, from a light-opaque resin. The bottom surface of the housing 101 is provided with a mounting hole 101a into which the portion of the mounting portion 11 provided with the bayonet 12 is inserted. A recess is provided around the periphery of the mounting hole 101a into which the bayonet 12 provided on the mounting portion 11 is inserted. Note that although the case where the mounting hole 101a is directly provided in the housing 101 has been exemplified, a mounting member having the mounting hole 101a may also be provided on the housing 101.

[0069] When attaching the vehicle lighting device 1 to the vehicle lamp 100, the portion of the mounting portion 11 where the bayonet 12 is provided is inserted into the mounting hole 101a, and the vehicle lighting device 1 is rotated. Then, for example, the bayonet 12 is held in a fitting portion provided on the periphery of the mounting hole 101a. This type of attachment method is called a twist lock.

[0070] The cover 102 is provided so as to cover the opening of the housing 101. The cover 102 is made of a light-transmitting resin or the like. The cover 102 may also have a function such as a lens.

[0071] Light emitted from the vehicle lighting device 1 is incident on the optical element 103. The optical element 103 reflects, diffuses, guides, and collects the light emitted from the vehicle lighting device 1, and forms a predetermined light distribution pattern. For example, the optical element 103 illustrated in FIG. 5 is a reflector. In this case, the optical element 103 reflects the light emitted from the vehicle lighting device 1 and forms a predetermined light distribution pattern.

[0072] The seal member 104 is provided between the flange 13 and the housing 101. The seal member 104 has an annular shape and is made of an elastic material such as rubber or silicone resin.

[0073] When the vehicle lighting device 1 is attached to the vehicle lamp 100, the seal member 104 is sandwiched between the flange 13 and the housing 101. Therefore, the seal member 104 can seal the internal space of the housing 101. Furthermore, the elastic force of the seal member 104 presses the bayonet 12 against the housing 101. Therefore, the vehicle lighting device 1 can be prevented from detaching from the housing 101.

[0074] The connector 105 is fitted to an end of the power supply terminal 31 exposed inside the connector holder 15. A power source or the like is electrically connected to the connector 105. Therefore, by fitting the connector 105 to the end of the power supply terminal 31, the power source or the like and the light-emitting element 22 can be electrically connected.

[0075] Furthermore, a seal member 105a is provided on the connector 105. When the connector 105 having the seal member 105a is inserted into the inside of the connector holder 15, the inside of the connector holder 15 is sealed so as to be watertight.

[0076] Although several embodiments of the present invention have been described above, these embodiments are presented by way of example only and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, modifications, etc. can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as set forth in the claims. Furthermore, the above-described embodiments can be implemented in combination with each other. [Explanation of symbols]

[0077] 1 Vehicle lighting device, 10 Socket, 20 Light-emitting module, 21 Board, 22 Light-emitting element, 22a Light-emitting element, 22b Light-emitting element, 26 Element, 26c Control element, 100 Vehicle lighting fixture, 101 Housing

Claims

1. Socket and; a substrate provided on one end side of the socket; a first light-emitting element provided on the substrate; four second light-emitting elements provided on the substrate; Equipped with defining a square luminance distribution region perpendicular to a central axis of the vehicle lighting device on the light irradiation side of the first light emitting element and the second light emitting element; a center of the luminance distribution region overlaps with a central axis of the vehicle lighting device; the luminance distribution region is equally divided into four square first regions whose corners overlap with the center of the luminance distribution region, each of the four square first regions is equally divided into nine square second regions; The length of one side of the second region is 0.8 mm, When the XY coordinates of the center of the luminance distribution area are (0, 0), The center of the first light-emitting element is located at (0,0), the centers of the four second light-emitting elements are located at (0.8, 0.8), (-0.8, 0.8), (0.8, -0.8), and (-0.8, -0.8); the luminance of the luminance distribution region is 90% or more of the total luminance of the light emitted from the vehicle lighting device, the luminance of one of the 20 second regions arranged along a side of the luminance distribution region is 2% or less of the total luminance; the luminance of one of the 16 second regions provided inside the 20 second regions is 3% or more and 10% or less of the overall luminance; A vehicle lighting device in which the planar shape of the first light-emitting element and the planar shape of the second light-emitting element are rectangular, and a first side of the rectangle of the first light-emitting element and a second side of the rectangle of the second light-emitting element opposite to the first side are parallel to each other.

2. 2. The vehicle lighting device according to claim 1, wherein the first light-emitting element and the second light-emitting element are upper and lower electrode type light-emitting elements.

3. The vehicle lighting device according to claim 1 or 2; a housing to which the vehicle lighting device is attached; A vehicle lighting fixture equipped with:

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